boost-react-native-bundle

<html> <head> <meta content="text/html; charset=windows-1252" http-equiv="content-type"> <title>BOOST_PP_FOR_r</title> <link rel="stylesheet" type="text/css" href="../styles.css"> </head> <body> <div style="margin-left: 0px;"> The <b>BOOST_PP_FOR_<i>r</i></b> macro represents a reentry into the <b>BOOST_PP_FOR</b> repetition construct. </div> <h4>Usage</h4> <div class="code"> <b>BOOST_PP_FOR_</b> ## <i>r</i>(<i>state</i>, <i>pred</i>, <i>op</i>, <i>macro</i>) </div> <h4>Arguments</h4> <dl> <dt>r</dt> <dd> The next available <b>BOOST_PP_FOR</b> repetition. </dd> <dt>state</dt> <dd> The initial state. </dd> <dt>pred</dt> <dd> A binary predicate of the form <i>pred</i>(<i>r</i>, <i>state</i>).  This macro must expand to an integer in the range of <i>0</i> to <b>BOOST_PP_LIMIT_MAG</b>.  <b>BOOST_PP_FOR</b> repeatedly expands <i>macro</i> while this predicate returns non-zero.  This macro is called with the next available <b>BOOST_PP_FOR</b> repetition and the current <i>state</i>. </dd> <dt>op</dt> <dd> A binary operation of the form <i>op</i>(<i>r</i>, <i>state</i>).  This operation is expanded by <b>BOOST_PP_FOR</b> with the next available <b>BOOST_PP_FOR</b> repetition and the current <i>state</i>.  This macro is repeatedly applied to the <i>state</i>, each time producing a new <i>state</i>, until <i>pred</i> returns <i>0</i>. </dd> <dt>macro</dt> <dd> A binary macro of the form <i>macro</i>(<i>r</i>, <i>state</i>).  This macro is expanded by <b>BOOST_PP_FOR</b> with the next available <b>BOOST_PP_FOR</b> repetition and the current <i>state</i>.  This macro is is repeated by <b>BOOST_PP_FOR</b> until <i>pred</i> returns <i>0</i>. </dd> </dl> <h4>Remarks</h4> <div> This macro expands to the sequence: <div> <i>macro</i>(<i>r</i>, <i>state</i>) <i>macro</i>(<i>r</i>, <i>op</i>(<i>r</i>, <i>state</i>)) ... <i>macro</i>(<i>r</i>, <i>op</i>(<i>r</i>, ... <i>op</i>(<i>r</i>, <i>state</i>) ... )) </div> </div> <div> At certain times, it may be necessary to perform the concatenation with <b>BOOST_PP_CAT</b> rather than the preprocessor token-pasting operator.  This happens when the <i>r</i> value is a macro invocation itself.  It needs a delay to allow it to expand.  The syntax in such a scenario becomes: <div> <b>BOOST_PP_CAT</b>(<b>BOOST_PP_FOR_</b>, <i>r</i>)(<i>state</i>, <i>pred</i>, <i>op</i>, <i>macro</i>) </div> </div> <h4>See Also</h4> <ul> <li><a href="cat.html">BOOST_PP_CAT</a></li> <li><a href="for.html">BOOST_PP_FOR</a></li> <li><a href="limit_mag.html">BOOST_PP_LIMIT_MAG</a></li> <li><a href="for_r_macros.html"><span style="color: gray;">Macros with R re-entrancy forms</span></a></li> </ul> <h4>Requirements</h4> <div> <b>Header:</b>  <a href="../headers/repetition/for.html"><boost/preprocessor/repetition/for.hpp></a> </div> <h4>Sample Code</h4> <div> <pre>#include <<a href="../headers/arithmetic/dec.html">boost/preprocessor/arithmetic/dec.hpp</a>> #include <<a href="../headers/arithmetic/inc.html">boost/preprocessor/arithmetic/inc.hpp</a>> #include <<a href="../headers/comparison/not_equal.html">boost/preprocessor/comparison/not_equal.hpp</a>> #include <<a href="../headers/punctuation/comma_if.html">boost/preprocessor/punctuation/comma_if.hpp</a>> #include <<a href="../headers/repetition/for.html">boost/preprocessor/repetition/for.hpp</a>> #include <<a href="../headers/tuple/elem.html">boost/preprocessor/tuple/elem.hpp</a>> #define PRED(r, state) \ <a href="not_equal.html">BOOST_PP_NOT_EQUAL</a>( \ <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>(4, 0, state), \ <a href="inc.html">BOOST_PP_INC</a>( \ <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>(4, 1, state) \ ) \ ) \ /**/ #define OP(r, state) \ ( \ <a href="inc.html">BOOST_PP_INC</a>( \ <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>(4, 0, state) \ ), \ <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>(4, 1, state), \ <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>(4, 2, state), \ <a href="inc.html">BOOST_PP_INC</a>( \ <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>(4, 3, state) \ ) \ ) \ /**/ #define MACRO(r, state) \ <a href="comma_if.html">BOOST_PP_COMMA_IF</a>( \ <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>(4, 3, state) \ ) template< \ <a href="for_r.html">BOOST_PP_FOR_</a> ## r( \ (0, <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>(4, 0, state), _, 0), \ PRED_2, OP, MACRO_2 \ ) \ > class <a href="cat.html">BOOST_PP_CAT</a>( \ <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>(4, 2, state), \ <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>(4, 0, state) \ ) \ /**/ #define PRED_2(r, state) \ <a href="not_equal.html">BOOST_PP_NOT_EQUAL</a>( \ <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>(4, 0, state), \ <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>(4, 1, state) \ ) \ /**/ #define MACRO_2(r, state) \ <a href="comma_if.html">BOOST_PP_COMMA_IF</a>( \ <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>(4, 0, state) \ ) class \ /**/ #define TEMPLATE_TEMPLATE(low, high, name) \ <a href="for.html">BOOST_PP_FOR</a>( \ (low, high, name, 0), \ PRED, OP, MACRO \ ) \ /**/ TEMPLATE_TEMPLATE(2, 4, T) /* expands to... template<class, class> class T2, template<class, class, class> class T3, template<class, class, class, class> class T4 */ </pre></div> <hr size="1"> <div style="margin-left: 0px;"> <i>� Copyright <a href="http://www.housemarque.com" target="_top">Housemarque Oy</a> 2002</i> <br> <i>� Copyright Paul Mensonides 2002<br> </i><i>� Copyright Edward Diener 2014</i><br> </div> <div style="margin-left: 0px;"> <p><small>Distributed under the Boost Software License, Version 1.0. (See accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p> </div> </body> </html>